Smoking article, and smoking article filter

ABSTRACT

This smoking article filter (4) has: a fine-powder-containing article (44) in which there is clumped together a raw powder that includes a taste component and/or an aroma component, the fine-powder-containing article being formed into a fine powder by the application of an external force; a cavity (43) in which the fine-powder-containing article is disposed; and a straightening member (40) provided in a connected row arrangement upstream of the cavity, the straightening member straightening the flow of a main smoke flow, which flows from upstream, to the cavity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of International Application PCT/JP2017/046188 filed on Dec. 22, 2017 and designated the U.S., the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a smoking article and a filter for a smoking article.

BACKGROUND ART

There is known a cigarette that allows powder in a filter to be inhaled to enjoy a taste, a scent, or both. For example, Patent document 1 discloses a smoking article with a filter including: a powder content that is a lump of base powder containing at least either one of a taste component or a flavoring component, the powder content being turned into powder by applying an external force thereto; a cavity where the powder content is accommodated; and a flow path through which the cavity is in communication with a mouthpiece end, the flow path letting the powder through.

CITATION LIST Patent Document

[Patent document 1] International Publication No. WO 2016/181843

SUMMARY OF INVENTION Technical Problem

Regarding the filter described in Patent document 1, an inner diameter of the flow path for the powder is reduced to be smaller than an outer diameter of the lump of powder content, thereby making it possible to reduce powder spillage, that is, spilling of the powder at an unintended timing such as during production or transportation. However, a typical technology has room for improvement in a delivery efficiency of a powder content in powder form in a cavity. In view of the above problems, an object of the present invention, which relates to a filter for a smoking article that allows powder containing at least either one of a taste component or a flavoring component to be inhaled, is to provide a technology that can improve a delivery efficiency of the powder during inhale more than ever before.

Solution to Problem

To solve the above problems, according to the present invention, a rectifying member is located continuously at an upstream side of a cavity where a powder content is accommodated, thereby allowing a mainstream smoke having flowed from an upstream side to be introduced into the cavity while rectified through the rectifying member.

More specifically, a smoking article according to the present invention includes: a tobacco rod including tobacco shreds; and a filter coupled to an end portion of the tobacco rod via a tipping paper, in which the filter includes: a powder content that includes a lump of base powder including at least either one of a taste component or a flavoring component and is turned into powder by application of an external force; a cavity where the powder content is accommodated; and a rectifying member that is located continuously at an upstream side of the cavity and rectifies and leads a mainstream smoke, which has flowed from an upstream side, to the cavity.

Examples of the smoking article include a cigarette, a cigar, a cigarillo, a smoking tool that allows for inhaling a smoke flavor, an aroma, or both of tobacco using electronic device heating, carbon heat source, or the like, and a non-heated smoking tool that allows for inhaling a taste, an aroma, or both of tobacco.

In addition, in the smoking article according to the present invention, the rectifying member may include: a low airflow resistance portion that is located at a part of a cross section over a range from a front end surface to a rear end surface and has a relatively low airflow resistance; and a high airflow resistance portion that is located at a rest of the cross section over the range from the front end surface to the rear end surface and is higher in airflow resistance than the low airflow resistance portion, the rectifying member leading the mainstream smoke, which has flowed from the upstream side through the low airflow resistance portion, to the cavity.

In addition, in the smoking article according to the present invention, the rectifying member may have a hollow path that penetrates the rectifying member in an axial direction, and include an airflow restricting portion that is formed at a region other than the hollow path and restricts a flow of the mainstream smoke, and the hollow path may correspond to the low airflow resistance portion and the airflow restricting portion may correspond to the high airflow resistance portion.

In addition, in the smoking article according to the present invention, the rectifying member may include a filter medium formed in a rod shape, and the low airflow resistance portion may be lower in a density of the filter medium than the high airflow resistance portion.

In addition, the smoking article according to the present invention further includes a mouthpiece filter unit that is located continuously at a downstream side of the cavity, and is provided with a powder supply path formed along an axial direction for allowing a mouthpiece end to communicate with the cavity and supplying the powder from the cavity to the mouthpiece end.

In addition, in the smoking article according to the present invention, the powder supply path may have a cross section configured to restrain entry of the powder content in a lump form.

In addition, in the smoking article according to the present invention, the low airflow resistance portion (for example, hollow path) of the rectifying member and the powder supply path of the mouthpiece filter unit may be located at positions corresponding to each other in a cross section of the filter.

In addition, in the smoking article according to the present invention, the low airflow resistance portion (for example, hollow path) of the rectifying member and the powder supply path of the mouthpiece filter unit may be located at positions not corresponding to each other in a cross section of the filter.

In addition, in the smoking article according to the present invention, the low airflow resistance portion (for example, hollow path) may be located in an outer peripheral region of the cross section of the rectifying member.

In addition, in the smoking article according to the present invention, a plurality of the low airflow resistance portions (for example, hollow paths) may be located in the outer peripheral region of the rectifying member.

In addition, in the smoking article according to the present invention, the plurality of low airflow resistance portions (for example, hollow paths) may be located at a regular interval along a circumferential direction of the outer peripheral region of the rectifying member.

In addition, in the smoking article according to the present invention, the low airflow resistance portion (for example, hollow path) may be located in a central region of the horizontal cross section of the rectifying member.

Here, the present invention may be identified as a filter for the above smoking article. Specifically, a filter for a smoking article according to the present invention includes: a powder content that includes a lump of base powder including at least either one of a taste component or a flavoring component and is turned into powder by application of an external force; a cavity where the powder content is accommodated; and a rectifying member that is located continuously at an upstream side of the cavity and rectifies and leads a mainstream smoke, which has flowed from an upstream side, to the cavity.

It should be noted that the means for solving the problems according to the present invention may be employed in combination as much as possible.

Advantageous Effects of Invention

According to the present invention, which relates to a filter for a smoking article that allows powder containing at least either one of a taste component or a flavoring component to be inhaled, it is possible to improve a delivery efficiency of the powder during inhale more than ever before.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an exterior perspective view of a cigarette according to Embodiment 1.

FIG. 2 illustrates a longitudinal sectional view of a relevant portion of the cigarette according to Embodiment 1.

FIG. 3 is a view illustrating a horizontal cross section of a mouthpiece filter unit according to Embodiment 1.

FIG. 4 is a view illustrating a horizontal cross section of a rectifying member according to Embodiment 1.

FIG. 5 is a view illustrating a state where a powder content in a filter according to Embodiment 1 is crushed into powder form.

FIG. 6 is a view indicating a list of ratios of change in powder delivery amount of Examples with respect to a control cigarette.

FIG. 7A is a view illustrating horizontal cross sections of rectifying members according to Examples.

FIG. 7B is a view illustrating horizontal cross sections of rectifying members according to Examples.

FIG. 8 is a view illustrating a smoking machine used for measurement of a powder delivery amount of each of Examples.

FIG. 9A is a longitudinal sectional view of a filter for a cigarette according to Modification Example 1.

FIG. 9B is a cross-sectional view of a rectifying member of the filter according to Modification Example 1.

FIG. 9C is a cross-sectional view of a mouthpiece filter unit of the filter according to Modification Example 1.

FIG. 10A is a longitudinal sectional view of a filter for a cigarette according to Modification Example 2.

FIG. 10B is a cross-sectional view of a rectifying member of the filter according to Modification Example 2.

FIG. 10C is a cross-sectional view of a mouthpiece filter unit of the filter according to Modification Example 2.

FIG. 11A is a longitudinal sectional view of a filter for a cigarette according to Modification Example 3.

FIG. 11B is a cross-sectional view of a rectifying member of the filter according to Modification Example 3.

FIG. 11C is a cross-sectional view of a mouthpiece filter unit of the filter according to Modification Example 3.

FIG. 12A is a longitudinal sectional view of a filter for a cigarette according to Modification Example 4.

FIG. 12B is a cross-sectional view of a rectifying member of the filter according to Modification Example 4.

FIG. 12C is a cross-sectional view of a mouthpiece filter unit of the filter according to Modification Example 4.

DESCRIPTION OF EMBODIMENTS

Detailed description will be made below on an embodiment of a filter-equipped cigarette, that is, an example of a smoking article according to the present invention, with reference to the drawings. Regarding dimensions, materials, shapes, relative locations, etc. of components described in the present embodiment, the technical scope of the invention is by no means limited only thereto unless otherwise specified.

Embodiment 1

FIG. 1 is an exterior perspective view of a cigarette 1 according to Embodiment 1. FIG. 2 is a longitudinal sectional view of a relevant portion of the cigarette 1 according to Embodiment 1. The cigarette 1 is a filter-equipped cigarette including a tobacco rod 2 and a filter 4 coupled to an end of the tobacco rod 2 via a tipping paper 3.

The tobacco rod 2 includes tobacco shreds 21 wrapped with a cigarette paper 22, being formed in a columnar shape (stick shape). The filter 4 is a member for filtering, when letting a mainstream smoke caused by smoking the cigarette 1 through, a smoke component from the mainstream smoke, and is formed in a columnar shape with substantially the same diameter as that of the tobacco rod 2.

The filter 4 is wrapped with a wrapping paper 45 and the tipping paper 3 and coupled to a rear end side of the tobacco rod 2 via the tipping paper 3. The tipping paper 3 wraps an end portion of the tobacco rod 2 and the filter 4 into one piece, thereby coupling (uniting) them. The end portion to be coupled to the filter 4 in a longitudinal direction (axial direction) of the tobacco rod 2 is hereinafter referred to as a “rear end” and an end portion opposite thereto as a “front end” (distal end). Further, an end portion to be coupled to the tobacco rod 2 in a longitudinal direction (axial direction) of the filter 4 is referred to as a “front end” and an end portion opposite to the front end as a “mouthpiece end.” Further, a cross section along a longitudinal direction (axial direction) of the cigarette 1 (tobacco rod 2, filter 4) is defined as a “longitudinal section” and a cross section along a direction orthogonal thereto as a “cross section.” Further, “upstream” and “downstream” refer to relative positional relationships based on a stream of the mainstream smoke. It should be noted that a reference symbol CL in FIG. 2 denotes a center axis of the cigarette 1 (tobacco rod 2, filter 4).

The filter 4 includes an upstream filter unit 41 coupled to the rear end side of the tobacco rod 2, a mouthpiece filter unit 42 located at a mouthpiece end side, a rectifying member 40 and a hollow cavity 43 formed between the upstream filter unit 41 and the mouthpiece filter unit 42, a powder content 44 accommodated in the cavity 43, etc. The upstream filter unit 41, the rectifying member 40, the cavity 43, and the mouthpiece filter unit 42 of the filter 4 are arranged in sequence from a front end side. The powder content 44, which is a lump of base powder containing at least either one of a taste component or a flavoring component, is turned into powder when crushed by a smoker.

The upstream filter unit 41 and the mouthpiece filter unit 42 each include, for example, a filter fiber such as acetate formed in a columnar shape and the upstream filter unit 41, the mouthpiece filter unit 42, and the rectifying member 40 are wrapped into one piece with the wrapping paper 45. The wrapping paper 45 used for the filter 4 may be a breathable wrapping paper usable for typical products or a non-breathable wrapping paper. A paper produced from a plant fiber is typically used as a material of the wrapping paper 45 but a sheet of a chemical fiber of a polymer (polypropylene, polyethylene, nylon, etc.) or a polymer sheet may be used or a metal foil such as aluminum foil may be used. It should be noted that a so-called non-wrap filter may be used as the filter 4. The non-wrap filter includes a filter material and an outer shell layer with which the filter material is formed in a cylindrical shape, and the outer shell layer can be obtained by thermoforming the filter material. In a case of using the non-wrap filter, a wrapping paper may be omitted.

A powder supply path 421 is provided in the mouthpiece filter unit 42 located at the mouthpiece end side, penetrating through the mouthpiece filter unit 42 in the axial direction, and the cavity 43 and the mouthpiece end are in communication with each other through the powder supply path 421. The powder supply path 421 has a cross section configured to restrain entry of the powder content 44 in a lump form. Meanwhile, the rectifying member 40, which is located continuously at an upstream side of the cavity 43, is a member for rectifying and leading a mainstream smoke having flowed from an upstream side thereof to the cavity 43. More specifically, the rectifying member 40 is located continuously in the axial direction between the upstream filter unit 41 and the cavity 43. The rectifying member 40, which includes: a low airflow resistance portion that is located at a part of the cross section over a range from a front end surface to a rear end surface and has a relatively low airflow resistance; and a high airflow resistance portion that is located at a rest of the cross section over the range from the front end surface to the rear end surface and is higher in airflow resistance than the low airflow resistance portion, is a member that leads the mainstream smoke, which has flowed from the upstream side through the low airflow resistance portion, to the cavity. More specifically, the rectifying member 40 includes a hollow hollow path 400 that penetrates the rectifying member 40 in the axial direction and an airflow restricting portion 401 formed at a region other than the hollow path 400, restricting a flow of the mainstream smoke through the airflow restricting portion 401. In this case, the hollow path 400 of the rectifying member 40 corresponds to the low airflow resistance portion and the airflow restricting portion 401 corresponds to the high airflow resistance portion. It should be noted that “restricting the flow of the mainstream smoke” may mean that the flow of the mainstream smoke is not fully prohibited through the airflow restricting portion 401 of the rectifying member 40 but permitted to slightly pass through the airflow restricting portion 401 of the rectifying member 40. That is, since the airflow restricting portion 401 has a relatively large airflow resistance as compared with the hollow path 400 of the rectifying member 40, an amount of the mainstream smoke passing through the airflow restricting portion 401 may become substantially zero or notably small as compared with at the hollow path 400. Details of the hollow path 400 and the airflow restricting portion 401 of the powder supply path 421 will be described later. Further, the filter 4 is wrapped with the tipping paper 3, thereby being united with the tobacco rod 2 into one piece.

A paper produced from a plant fiber is typically used as the tipping paper 3A but a sheet of a chemical fiber of a polymer (polypropylene, polyethylene, nylon, etc.) or a polymer sheet may be used or a metal foil such as aluminum foil may be used. It should be noted that the filter 4 may contain a flavoring agent such as menthol. A method of adding the flavoring agent is not limited to a particular one; a known method is providing a string-shaped substance with the flavoring agent adsorbed thereto in the filter 4, containing the flavoring agent in a filling in the filter 4, or providing a material prepared by solidifying the flavoring agent, such as a capsule, in the filter 4, for example.

A plurality of vents (hereinafter referred to as “upstream filter unit region vent”) 31, through which air (outside air) for ventilation is introduced into the filter 4 to dilute the mainstream smoke, are annularly formed in the tipping paper 3 and the wrapping paper 45 at a position corresponding to the upstream filter unit 41. A non-breathable or less-breathable wrapping paper may be used as the wrapping paper 45. Further, by adjusting an opening area of the upstream filter unit region vent 31 (in a case of providing a plurality of upstream filter unit region vents 31, a total opening area), it is possible to adjust a Vf value (a ratio of an inflow rate of air from the filter to a total airflow rate). A tar value of the cigarette is designed in accordance with the Vf value, thereby allowing the powder formed by crushing the powder content 44 to be delivered as much as possible.

The cavity 43 is a space defined inside the filter 4, in particular, a columnar space surrounded by a surface of a rear end of the upstream filter unit 41, a surface of a front end of the mouthpiece filter unit 42, and the wrapping paper 45. The cavity 43 only has to have a size sufficient to accommodate the powder content 44. In a case of accommodating a plurality of powder contents 44, the cavity 43 needs to have a size sufficient to accommodate the plurality of powder contents 44. Further, a shape of the cavity 43 is not limited to a particular one.

The powder content 44 is a spherical lump of the base powder and turned into powder when an external force is applied thereto. The external force is, for example, a force stronger than a force to be applied during production or transportation or a force stronger than an inhale force during smoking. The external force is exemplified by a force (crushing force) applied by a smoker with his or her fingers. For example, a breaking strength for powdering the powder content 44 is in a range from 5 N to 60 N. The breaking strength for powdering the powder content 44 is preferably in a range from 20 N to 30 N, and more preferably in a range from 20 N to 25 N. Further, a shape of the powder content 44 is not limited to a particular one and may be an ellipsoid, a column, a hollow cylinder, a circular cone, a polygonal pyramid, a torus, a polyhedron such as a cube or a rectangular parallelepiped, or a combination thereof. Further, the base powder that constitutes the powder content 44 at least partly has a particle size allowing for passing through the powder supply path 421. For example, the particle size of the base powder may be set in a range from 10 μm to 300 μm.

The powder content 44 may be produced by mixing a nucleating agent, that is, the base powder, with an adequate amount of water added thereto and then forming and drying it. Further, a binder may be added as a material of the powder content 44. Further, a flavoring agent may be added to the nucleating agent along with water. As the nucleating agent, monosaccharide, disaccharide, polysaccharide, or derivatives thereof is usable. Examples include ketotriose (dihydroxyacetone), aldotriose (glyceraldehyde), ketotetrose (erythrulose), aldotetrose (erythrose, threose), pentose ketopentose (ribulose, xylulose), aldopentose (ribose, arabinose, xylose, lyxose), deoxysugar (deoxyribose), ketohexose (psicose, fructose, sorbose, tagatose), aldohexose (allose, altrose, glucose, mannose, gulose, idose, galactose, talose), deoxysugar (fucose, fuculose, rhamnose), sedoheptulose, sucrose, lactose, maltose, trehalose, turanose, cellobiose, raffinose, melezitose, maltotriose, acarbose, stachyose, glucose, starch (amylose, amylopectin), cellulose, dextrin, glucan, and fructose. These monosaccharide, disaccharide, polysaccharide, or derivatives thereof may be used solely or mixed in use. The nucleating agent is preferably substantially soluble in a mouth.

Further, as the binder, water soluble polymers such as dextrin, gelatin, gum arabic, polyvinyl alcohol, and carboxymethyl cellulose are usable. An addition amount of the binder is preferably 10 wt % or less with respect to the nucleating agent.

The flavoring agent being added to the nucleating agent is not limited to a particular one and an existing flavoring agent may be used; however, a powder flavoring agent and an oil flavoring agent are particularly suitable. Typical examples of the powder flavoring agent include chamomile, fenugreek, menthol, mint, cinnamon, and herb that are in powder form. Further, typical examples of the oil flavoring agent include lavender, cinnamon, cardamom, celery, clove, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon, orange, mint, cinnamon, caraway, cognac, jasmine, chamomile, menthol, cassia, ylang-ylang, sage, spearmint, fennel, pimento, ginger, anise, coriander, and coffee. These powder flavoring agents and oil flavoring agents may be used solely or mixed in use. In a case of using the powder flavoring agent, a grain size thereof is preferably 500 μm or less. The flavoring agent is preferably substantially soluble in liquid or a mouth. Further, an addition amount of the flavoring component is preferably 10 wt % or less with respect to the nucleating agent.

Examples of the taste component include citric acid, tartaric acid, glutamic acid Na, neotame, thaumatin, stevia, sorbitol, xylitol, erythritol, aspartame, rutin, hesperidin, oxalic acid, tannic acid, catechin, naringin, quinine, quinic acid, limonin, caffeine, capsaicin, vitamins, amino acids, polyphenols, alginic acid, flavonoid, and lecithin. The taste component is preferably substantially soluble in liquid or a mouth. An addition amount of the taste component is preferably 10 wt % or less with respect to the nucleating agent. It should be noted that the powder content 44 may be in a form of a plastic capsule containing powder, a tablet compact, or granules.

Here, FIG. 3 is a view illustrating a cross section of the mouthpiece filter unit 42 according to Embodiment 1. As illustrated in FIG. 3, the cross section of the powder supply path 421 according to the present embodiment is in a form of an opening having a shape of a single windmill as a whole. More specifically, in the cross section of the mouthpiece filter unit 42, the powder supply path 421 has a central connection portion 4210 located at a central side of the cross section of the mouthpiece filter unit 42 and a plurality of holes 4211 that extend from the central connection portion 4210 toward an outer peripheral side of the cross section of the mouthpiece filter unit 42. Here, an opening area of each of the holes 4211 is relatively large as compared with an opening area of the central connection portion 4210.

The plurality of holes 4211 of the powder supply path 421, each of which is in a blade shape, radially extend in mutually different directions from the central connection portion 4210. Further, distal ends (end portions at a side opposite the central connection portion 4210) of the holes 4211 are located at positions spaced from the wrapping paper 45 of the mouthpiece filter unit 42 with the filter fiber, which constitutes the mouthpiece filter unit 42, interposed between the distal ends of the holes 4211 and the wrapping paper 45. Further, in an example illustrated in FIG. 3, the powder supply path 421 has three holes 4211 that radially extend from the central connection portion 4210 toward the outer peripheral side. Further, an opening width of each of the holes 4211 of the powder supply path 421 is gradually widened from a side of the base end (an end portion connected with the central connection portion 4210) toward a side of the distal end. For this reason, each of the holes 4211 of the powder supply path 421 has a relatively wide (large) opening width at an outer peripheral region 4211 a located at the outer peripheral side of the cross section of the mouthpiece filter unit 42 as compared with at a central region 4211 b located at the central side of the cross section. The powder supply path 421 of the mouthpiece filter unit 42 configured as described above has a cross section that restrains entry of the spherical powder content 44 that is a lump of the base powder, preventing the powder content 44 from moving downstream of the cavity 43. Specifically, the powder supply path 421 has a cross-sectional dimension smaller than a diameter of the powder content 44 in a lump form.

Next, the rectifying member 40 will be described. FIG. 4 is a view illustrating a cross section of the rectifying member 40 according to Embodiment 1. As illustrated in FIG. 4, the rectifying member 40 has the single hollow path 400 with a circular cross section concentric with the center axis CL. Hereinafter, such a configuration form of the hollow path 400 is also referred to as a “single-hole type.” The rectifying member 40 may include a molded body of resin, metal, or the like and the molded body is provided with the hollow hollow path 400, thereby being able to form the remaining region as the airflow restricting portion 401. Alternatively, the rectifying member 40 may be a center hole filter segment including a filter fiber such as acetate formed in a columnar shape with a through hole provided at an axial center portion as the mouthpiece filter unit 42, for example. The hollow path 400 has a cross section configured to restrain entry of the spherical powder content 44 that is a lump of the base powder. Specifically, the hollow path 400 is designed to have a dimension smaller than the diameter of the powder content 44 in a lump form.

<Effects>

In the cigarette 1 according to the present embodiment, the powder supply path 421 of the mouthpiece filter unit 42 has the cross section that does not allows the powder content 44 in lump form to pass therethrough. For this reason, since the powder content 44 in lump form accommodated in the cavity 43 does not pass through the powder supply path 421, it is possible to reduce discharge of the powder content 44 in lump form out of the filter 4 through the powder supply path 421. Meanwhile, when a smoker crushes the powder content 44 in lump form by, for example, applying an external force, turning the powder content 44 into powder form, the powder of the powder content 44 is allowed to pass through the powder supply path 421. As a result, the smoker is allowed to easily inhale the powder at a desired timing, enjoying a taste from the taste component, a scent from the flavoring component, or both.

Meanwhile, the filter 4 according to the present embodiment includes the rectifying member 40 located continuously at the upstream side of the cavity 43. The rectifying member 40 according to the present embodiment is provided with, at a part of the cross section, the hollow hollow path 400 that extends in the axial direction and leads the mainstream smoke to the cavity 43 and, at the rest thereof, the airflow restricting portion 401 that restricts the flow of the mainstream smoke, thus allowing for rectifying the mainstream smoke to flow locally at a specific region in the cross section of the cavity 43. This makes it possible to increase a flow speed of the mainstream smoke through the hollow path 400. Further, as a result of leading the high-speed mainstream smoke, which has been increased in flow speed through the hollow path 400, into the cavity 43, it is possible to efficiently raise the powder of the powder content 44 accumulated in the cavity 43 and deliver the powder of the powder content 44 through the powder supply path 421 of the mouthpiece filter unit 42 at the downstream with efficiency.

It should be noted that the hollow path 400 of the rectifying member 40 according to the present embodiment is of the single-hole type as illustrated in FIG. 5, so that the hollow path 400 can reliably have a certain-size hollow cross section with a cross-sectional area that is not extremely thinned. This makes it possible to prevent an extreme reduction in the flow rate of the mainstream smoke, which is at a high speed, flowing through the hollow path 400. As a result, since some moderate amount of the high-speed mainstream smoke can be led into the cavity 43, the powder of the powder content 44 can be efficiently delivered by supplying the mainstream smoke into the cavity 43 with a force large enough to raise the powder of the powder content 44 accumulated in the cavity 43. It should be noted that the form of the hollow path 400 of the rectifying member 40 is not limited to the above single-hole type and a variety of forms are applicable. In this regard, other implementations of the hollow path 400 will be described later.

Further, since the rectifying member 40 is located continuously upstream of the cavity 43 to improve a delivery efficiency of the powder of the powder content 44 in the cavity 43, the filter 4 according to the present embodiment eliminates the necessity of providing a side surface of the cavity 43 with a plurality of vents (hereinafter referred to as “cavity region vent”) through which air (outside air) for ventilation is introduced into the filter 4 to dilute the mainstream smoke. This makes it possible to increase a strength of the cavity 43 to lower bendability.

However, the side surface of the cavity 43 may be provided with the cavity region vent. In this case, a wrapping paper with a high air-permeability (breathability) is used as the wrapping paper 45, thereby allowing the air introduced from the outside through the cavity region vent formed in the tipping paper 3 to pass therethrough into the cavity 43 without the necessity of piercing a hole in a cavity region vent in the wrapping paper 45. This is beneficial in increasing a strength of the wrapping paper 45 and making it less bendable. Further, a wrapping paper that is not or less breathable may be used as the wrapping paper 45. In this case, the wrapping paper 45 desirably has a vent that is open at a position corresponding to the cavity region vent. It should be noted that a pre-holed tipping paper that is provided with the cavity region vent in advance is preferably used as the tipping paper 3. This makes it unlikely to cause damage to the powder content 44 accommodated in the cavity 43 as compared with a case where the cavity region vent is formed using, for example, an on-machine laser.

Moreover, the powder supply path 421 according to the present embodiment has the plurality of holes 4211 that extend in mutually different directions from the central connection portion 4210, which is located at the central side of the cross section of the mouthpiece filter unit 42, toward the outer peripheral side. Here, although an increase in a cross-sectional area of the powder supply path 421 is favorable in terms of an increase in a delivery amount (supply amount) of the powder during inhale by the smoker, simply increasing the cross-sectional area of the powder supply path 421 leads to frequent occurrence of unintended spilling of the powder (powder spillage) not during inhale by the smoker. Examples of the above unintended powder spillage include a case where the powder spills outside through the powder supply path 421 as a mouthpiece side of the filter 4 is turned downward while the smoker does not put the filter 4 in his or her mouth.

Accordingly, regarding the powder supply path 421 according to the present embodiment, the plurality of holes 4211 extend in mutually different directions from the central connection portion 4210, which is located at the central side of the cross section of the mouthpiece filter unit 42, toward the outer peripheral side, thus allowing opening regions not to be concentrated at one spot in the cross section of the mouthpiece filter unit 42 but to be distributed at the outer peripheral side. This makes it possible to ensure, after the powder content 44 in lump form is crushed into powder form, a total opening area enough to ensure a sufficient delivery amount (supply amount) of the powder during inhale while reducing unintended powder spillage not during inhale. In particular, the powder supply path 421 according to the present embodiment has the plurality of holes 4211 that radially extend from the central connection portion 4210 toward the outer peripheral side, so that the opening regions can be more favorably distributed in the cross section of the mouthpiece filter unit 42, making it much easier to ensure the delivery amount of the powder during inhale while favorably reducing unintended powder spillage after the powder content 44 is crushed.

Here, when the smoker puts the filter 4 of the cigarette 1 in his or her mouth for inhale, the powder of the crushed powder content 44 in the cavity 43 is accumulated at the outer peripheral side of the cavity 43 (wrapping paper 45). Thus, distributing the opening regions of the powder supply path 421 more at the outer peripheral side of the mouthpiece filter unit 42 is favorable in terms of an increase in the delivery amount of the powder during inhale. Accordingly, since the central connection portion 4210 is relatively small and the holes 4211 each have a larger opening area than the central connection portion 4210, the powder supply path 421 according to the present embodiment allows for increasing the delivery amount of the powder during inhale. Moreover, since each of the holes 4211 of the powder supply path 421 has a relatively wide opening width at the outer peripheral region 4211 a as compared with at the central region 4211 b, a large opening area is easily ensured at the outer peripheral side of the cross section of the mouthpiece filter unit 42. As a result, it is possible to further increase the delivery amount of the powder during inhale.

Further, the distal ends of the holes 4211 of the powder supply path 421 are spaced from the wrapping paper 45 of the mouthpiece filter unit 42 with the filter fiber interposed between each of the distal ends of the holes 4211 and the wrapping paper 45. Since the holes 4211 are formed in a manner not to extend until the distal ends of the holes 4211 reach the wrapping paper 45 as described above, an edge portion (outermost peripheral portion) of the mouthpiece filter unit 42 does not become an opening and, thus, it is possible to further reduce unintended powder spillage not during inhale.

Further, regarding the powder supply path 421 according to the present embodiment, the base ends of the plurality of holes 4211 are connected to each other via the central connection portion 4210, becoming a continuous opening. For this reason, in producing the mouthpiece filter unit 42, it is possible to produce the mouthpiece filter unit 42 using a single mandrel and evenly fill a region other than the powder supply path 421 in the cross section of the mouthpiece filter unit 42 with the filter fiber. That is, it is possible to stabilize a production quality of the mouthpiece filter unit 42. It should be noted that the form of the powder supply path 421 of the mouthpiece filter unit 42 is not limited to a windmill type as illustrated in FIG. 3 and a variety of forms are applicable. In this regard, other implementations of the powder supply path 421 will be described later.

Further, specifications that cause less bend or crease when a smoker crushes the powder content 44 in lump form by applying an external force thereto are preferably selected for the wrapping paper 45 of the filter 4. For example, a basis weight of the wrapping paper 45 is preferably in a range from 50 to 200 g/m² and more preferably determined in a range from 50 to 110 g/m². Further, the air-permeability (breathability) of the wrapping paper 45 is preferably 1000 to 10000 [C.U]. Further, a total length of the filter 4 and lengths of the upstream filter unit 41, the rectifying member 40, the cavity 43, and the mouthpiece filter unit 42 are not limited to particular ones.

EXAMPLES

Next, the present invention will be further specifically described with reference to Examples but the present invention is by no means limited to the description of Examples below insofar as being within the spirit thereof. The cigarettes 1 according to Examples 1 to 4 different in the hollow path 400 of the rectifying member 40 of the filter 4 and a control cigarette not provided with the rectifying member 40 were produced and a test for measuring the delivery amount of the powder during inhale was performed. Regarding the filters 4 of Examples, the length of the upstream filter unit 41 was 9 mm, the length of the rectifying member 40 was 5 mm, the length of the cavity 43 was 6 mm, and the length of the mouthpiece filter unit 42 was 7 mm. Further, the base powder of the powder content 44 was accommodated in the cavity 43 on the assumption of a crushed state of the powder content 44. As the base powder of the powder content 44, 50 mg lactose (Pharmatose 100M, manufactured by DFE pharma) was used. Meanwhile, regarding a filter for the control cigarette, the length of the upstream filter unit 41 was 14 mm, the length of the cavity 43 was 6 mm, and the length of the mouthpiece filter unit 42 was 7 mm. In addition, regarding the filter for the control cigarette, the rectifying member 40 was not provided and the upstream filter unit 41, the cavity 43, and the mouthpiece filter unit 42 were aligned in the axial direction.

FIG. 6 indicates a list of ratios of change in powder delivery amount of Examples with respect to the control cigarette. The ratio of change in powder delivery amount herein refers to a ratio of the powder delivery amount of each of Examples on the basis of the powder delivery amount of the control cigarette.

FIG. 7A and FIG. 7B illustrate cross sections of the rectifying member 40 according to Examples. Example 1 is of the “single-hole type”, Example 2 is of a “three-hole type”, Example 3 is of a “twelve-hole type”, and Example 4 is of a “twelve-outer-peripheral-groove type.” Regarding the “single-hole type” of Example 1, the hollow path 400 having a single circular cross section was provided at a central portion of the cross section of the rectifying member 40 and a cross-sectional area of an opening was 6.0 mm². Meanwhile, regarding the “three-hole type” of Example 2, three hollow paths 400 each having a circular cross section were arranged in a region near an outer peripheral portion of the rectifying member 40 at regular pitches, that is, every 120°, along a circumferential direction and a total cross-sectional area of openings was 5.3 mm². Meanwhile, regarding the “twelve-hole type” of Example 3, twelve hollow paths 400 each having a circular cross section were arranged at the outer peripheral portion of the cross section of the rectifying member 40 at regular pitches, that is, every 30°, along a circumferential direction and a total cross-sectional area of openings was 6.2 m². Meanwhile, regarding the “twelve-outer-peripheral-groove type” of Example 4, twelve hollow paths 400 each in a form of semicircular grooves were arranged at the outer peripheral portion of the rectifying member 40 at regular pitches, that is, every 30°, along a circumferential direction and a total cross-sectional area of openings was 9.2 mm². It should be noted that all of Examples 1 to 4 and the control cigarette share common specifications of the powder supply path 421 of the mouthpiece filter unit 42, which has a windmill-shaped cross section illustrated in FIG. 3.

A smoking machine illustrated in FIG. 8 was used to measure the powder delivery amount. In Examples, an inhale experiment was performed in an unlit state using a single-holder smoking machine manufactured by Borgwaldt KC GmbH and the powder delivery amount was measured. In performing the inhale experiment, an inhale flow rate was 35 mL/2 sec, the number of inhale actions was five, and the number of cigarettes for measurement was five. Further, a powder collecting pad (Cambridge pad) was removed every inhale and measured in weight with an electronic balance and the powder delivery amount was calculated from a difference in weight between before and after inhale.

As indicated in FIG. 6, it has been found that all of Examples 1 to 4 achieve an increase in powder delivery amount as compared with the control cigarette where the rectifying member 40 is not provided. In particular, in comparison between Example 1 (single-hole type) and Example 2 (three-hole type), Example 2 (three-hole type) was larger in an increasing rate of the powder delivery amount, although being smaller in a total cross-sectional area of the openings as compared with Example 1 (single-hole type). This may be supposed to be because the hollow paths 400 of the rectifying member 40 according to Example 2 (three-hole type) are located in an outer peripheral region of the cross section of the rectifying member 40, causing airflow to intensively and efficiently hit lactose powder accumulated on a wrapping paper located at an outer periphery of the cavity.

Modification Examples

Next, description will be made on a relationship between the hollow path 400 of the rectifying member 40 and the powder supply path 421 of the mouthpiece filter unit 42 of the filter 4 according to Embodiment 1. FIG. 9A is a longitudinal sectional view of a filter 4A of a cigarette 1A according to Modification Example 1. FIG. 9B is a cross-sectional view of the rectifying member 40 of the filter 4A according to Modification Example 1. FIG. 9C is a cross-sectional view of the mouthpiece filter unit 42 of the filter 4A according to Modification Example 1. As illustrated in FIGS. 9A to 9C, regarding the filter 4A according to Modification Example 1, the hollow path 400 of the rectifying member 40 and the powder supply path 421 of the mouthpiece filter unit 42 are each formed as the “single-hole type”, being located at a middle of a cross section of the filter 4A. Further, the hollow path 400 of the rectifying member 40 and the powder supply path 421 of the mouthpiece filter unit 42 of the filter 4A are located at positions corresponding to each other in the cross section of the filter 4A. Such locations of the hollow path 400 of the rectifying member 40 and the powder supply path 421 of the mouthpiece filter unit 42 opposed to each other make it possible to smoothly lead the mainstream smoke (airflow), which has been led to the cavity 43 while rectified through the hollow path 400 of the rectifying member 40, to the powder supply path 421 opposed to the hollow path 400 and, consequently, efficiently deliver the powder of the powder content 44 accumulated in the cavity 43 with the stream of the mainstream smoke.

FIG. 10A is a longitudinal sectional view of a filter 4B of a cigarette 1B according to Modification Example 2. FIG. 10B is a cross-sectional view of the rectifying member 40 of the filter 4B according to Modification Example 2. FIG. 10C is a cross-sectional view of the mouthpiece filter unit 42 of the filter 4B according to Modification Example 2. As illustrated in FIGS. 10A to 10C, regarding the filter 4B according to Modification Example 2, the hollow path 400 of the rectifying member 40 and the powder supply path 421 of the mouthpiece filter unit 42 are each formed as the “three-hole type.” Thus, since the hollow path 400 of the rectifying member 40 and the powder supply path 421 of the mouthpiece filter unit 42 are located at positions corresponding to each other in the cross section of the filter 4B, Modification Example 2 also allows for efficiently delivering the powder of the powder content 44 accumulated in the cavity 43 with the stream of the mainstream smoke.

FIG. 11A is a longitudinal sectional view of a filter 4C of a cigarette 1C according to Modification Example 3. FIG. 11B is a cross-sectional view of rectifying member 40 of the filter 4C according to Modification Example 3. FIG. 11C is a cross-sectional view of the mouthpiece filter unit 42 of the filter 4C according to Modification Example 3. As illustrated in FIGS. 11A to 11C, regarding the filter 4C according to Modification Example 3, the hollow path 400 of the rectifying member 40 is formed as the “three-hole type” and the powder supply path 421 of the mouthpiece filter unit 42 is formed as the “single-hole type.” For this reason, in Modification Example 3, the hollow path 400 of the rectifying member 40 and the powder supply path 421 of the mouthpiece filter unit 42 are located at positions not corresponding to each other in the cross section of the filter 4C. Such locations of the hollow path 400 of the rectifying member 40 and the powder supply path 421 of the mouthpiece filter unit 42 not opposed to each other cause temporary turbulence in the cavity 43 in the stream of the mainstream smoke (airflow), which has been led to the cavity 43 while rectified through the hollow path 400 of the rectifying member 40, thereby facilitating the raising of the powder of the powder content 44 accumulated in the cavity 43 and, consequently, making it possible to efficiently deliver the powder of the powder content 44 with the stream of the mainstream smoke.

FIG. 12A is a longitudinal sectional view of a filter 4D of a cigarette 1D according to Modification Example 4. FIG. 12B is a cross-sectional view of the rectifying member 40 of the filter 4D according to Modification Example 4. FIG. 12C is a cross-sectional view of the mouthpiece filter unit 42 of the filter 4D according to Modification Example 4. As illustrated in FIGS. 12A to 12C, regarding the filter 4D according to Modification Example 4, the hollow path 400 of the rectifying member 40 is formed as an “eight-hole type” and the powder supply path 421 of the mouthpiece filter unit 42 is formed as the “three-hole type.” Thus, since the hollow path 400 of the rectifying member 40 and the powder supply path 421 of the mouthpiece filter unit 42 are located at positions not corresponding to each other in the cross section of the filter 4D, Modification Example 4 also allows for causing temporary turbulence in the cavity 43 in the stream of the mainstream smoke (airflow), which has been led to the cavity 43 while rectified through the hollow path 400 of the rectifying member 40, in the cavity 43. As a result, the raising of the powder of the powder content 44 accumulated in the cavity 43 is facilitated, making it possible to efficiently deliver the powder of the powder content 44 with the stream of the mainstream smoke.

It should be noted that the rectifying members 40 according to the above embodiments and modification examples may each include a filter medium (element) formed in a rod shape. In such a case where the rectifying member 40 includes a rod-shaped filter medium, a portion corresponding to the hollow path 400 in a cross section of the filter medium may have a relatively low filter-medium density to function as the low airflow resistance portion while a portion corresponding to the airflow restricting portion 401 may have a relatively high filter-medium density to function as the high airflow resistance portion. This allows the mainstream smoke having flowed from the upstream to preferentially pass through the low airflow resistance portion of the rectifying member 40, introducing the mainstream smoke into the cavity 43 while rectifying it. In the case where the rectifying member 40 includes the filter medium formed in a rod shape as described above, it is advantageous in producing the rectifying member 40 easily and inexpensively. Further, in the case where the rectifying member 40 has a function as a filter medium that filters the mainstream smoke as described above, providing the upstream filter unit 41 may be omitted and thus a man-hour for a production process can be reduced. Further, even when the upstream filter unit 41 is omitted, the filter medium is located all over the cross section of the rectifying member 40, making it possible to restrain, for example, a granular or powdery substance, such as the tobacco shreds 21 of the tobacco rod 2, upstream of the rectifying member 40 from entering downstream of the rectifying member 40.

The preferred embodiments of the present invention have been described above; however, a filter for a smoking article according to the present invention may be implemented by combining the embodiments as much as possible.

REFERENCE SIGNS LIST

-   1 . . . cigarette -   2 . . . tobacco rod -   3 . . . tipping paper -   4 . . . filter -   40 . . . rectifying member -   41 . . . upstream filter unit -   42 . . . mouthpiece filter unit -   43 . . . cavity -   44 . . . powder content -   45 . . . wrapping paper -   400 . . . hollow portion -   401 . . . airflow restricting portion -   421 . . . powder supply path -   4210 . . . central connection portion -   4211 . . . hole 

What is claimed is:
 1. A smoking article comprising: a tobacco rod including tobacco shreds; and a filter coupled to an end portion of the tobacco rod via a tipping paper, wherein the filter includes: a powder content that includes a lump of base powder including at least either one of a taste component or a flavoring component and is turned into powder by application of an external force; a cavity where the powder content is accommodated; and a rectifying member that is located continuously at an upstream side of the cavity and rectifies and leads a mainstream smoke, which has flowed from an upstream side, to the cavity.
 2. The smoking article according to claim 1, wherein the rectifying member includes: a low airflow resistance portion that is located at a part of a cross section over a range from a front end surface to a rear end surface and has a relatively low airflow resistance; and a high airflow resistance portion that is located at a rest of the cross section over the range from the front end surface to the rear end surface and is higher in airflow resistance than the low airflow resistance portion, the rectifying member leading the mainstream smoke, which has flowed from the upstream side through the low airflow resistance portion, to the cavity.
 3. The smoking article according to claim 2, wherein the rectifying member has a hollow path that penetrates the rectifying member in an axial direction, and includes an airflow restricting portion that is formed at a region other than the hollow path and restricts a flow of the mainstream smoke, and the hollow path corresponds to the low airflow resistance portion and the airflow restricting portion corresponds to the high airflow resistance portion.
 4. The smoking article according to claim 2, wherein the rectifying member includes a filter medium formed in a rod shape, and the low airflow resistance portion is lower in a density of the filter medium than the high airflow resistance portion.
 5. The smoking article according to claim 2, further comprising a mouthpiece filter unit that is located continuously at a downstream side of the cavity, and is provided with a powder supply path formed along an axial direction for allowing a mouthpiece end to communicate with the cavity and supplying the powder from the cavity to the mouthpiece end.
 6. The smoking article according to claim 5, wherein the powder supply path has a cross section configured to restrain entry of the powder content in a lump form.
 7. The smoking article according to claim 5, wherein the low airflow resistance portion of the rectifying member and the powder supply path of the mouthpiece filter unit are located at positions corresponding to each other in a cross section of the filter.
 8. The smoking article according to claim 5, wherein the low airflow resistance portion of the rectifying member and the powder supply path of the mouthpiece filter unit are located at positions not corresponding to each other in a cross section of the filter.
 9. The smoking article according to claim 2, wherein the low airflow resistance portion is located in an outer peripheral region of the cross section of the rectifying member.
 10. The smoking article according to claim 9, wherein a plurality of the low airflow resistance portions are located in the outer peripheral region of the rectifying member.
 11. The smoking article according to claim 10, wherein the plurality of low airflow resistance portions are located at a regular interval along a circumferential direction of the outer peripheral region of the rectifying member.
 12. The smoking article according to claim 2, wherein the low airflow resistance portion is located in a central region of the cross section of the rectifying member.
 13. A filter for a smoking article, the filter comprising: a powder content that includes a lump of base powder including at least either one of a taste component or a flavoring component and is turned into powder by application of an external force; a cavity where the powder content is accommodated; and a rectifying member that is located continuously at an upstream side of the cavity and rectifies and leads a mainstream smoke, which has flowed from an upstream side, to the cavity. 